Some issues to notice in the research and quality evaluation of external preparations of traditional Chinese medicine

External preparations of traditional Chinese medicine inherits features of traditional Chinese pharmaceuticals while presenting the application of modern scientific technology in the field of medicine preparations. This paper will discuss some issues that investigators should pay attention to when they work on the preparations, such as the rationality of selecting drug dosage forms, how to select and handle drug auxiliary materials, and how to study medicinal material processing techniques. All these issues were found out during the drug evaluation cases in recent years.